1. Field of the Invention
The present invention relates to a display apparatus, and more particularly, to a display apparatus in a camera having rotating elements for indicating photographic information.
2. Description of the Related Art
Conventional analog-type display devices are known in which either one or a plurality of rotary pointers are used to indicate various information whereby the rotary pointers point to indices representative of the different information. In particular, cameras which use rotary pointer analog-type display devices are known in which information such as frame count, shutter speed, range value, self timer mode information, exposure correction information, etc. may be displayed individually or in various combinations. In order to indicate specific information, rotary pointers in known types of camera display devices are rotated by means of a stepping motor to point to display indices located above the pointer on scales containing the photographic information. For example, Japanese Patent Application No. 3-214613 discloses a small clock type display device wherein only one kind of information is displayed using a stepping motor to rotate a pointer.
A problem with these known types of rotating pointer camera displays, however, is that it is difficult to accurately display all the needed information in limited space on the camera body. Furthermore, it is difficult to accurately display all the needed information in a manner which quickly and easily conveys the information to a camera user. Still further, the known types of display devices sometime display erroneous information. As a result of the above-noted deficiencies, a camera operator may take poor photographs, or may miss photograph opportunities completely.
The above-noted problems have occurred in conventional display devices which use stepping motors to drive the rotation of display pointers. The stepping motors are small in size, highly reliable, and inexpensive and, therefore, their use to drive rotating pointers in display devices of cameras has been desirable. However, since the stepping motor is turned off when the electric power supply of a device using the stepping motor is turned off, the pointer of a display device will remain at the position at which it was located at the time power is turned off. The device in question may be in a state in which it is still operable, and thus, a user receives erroneous information regarding the operative state of the device.
In addition to displaying erroneous information, prior art rotary pointer type display devices suffer from difficulties in easily reading the display. In particular, rotary pointer type display devices are known which display a photographic frame count of the film. An example of such a display device is illustrated in FIG. 5. As seen in FIG. 5, a display 27 includes a rotary display pointer 25, which is geared to the film advance, and displays the current photographic frame count by pointing to a respective index on a corresponding display scale 27 in accordance with the film advance. However, in these prior art display devices, intervals between the indices indicating the frame count are small, and, therefore, it is difficult for a viewer of the display to determine the present photographic frame count. Furthermore, when the number of frames remaining becomes small, the possibility of missing photograph opportunities arises due to misreading of the remaining number of frames.
Conventional display devices are known in which a combination of different types of camera information is displayed pictorially using a liquid crystal display, or through the use of rotary dials which combine the setting and the display of photographic conditions such as shutter timing, stop value, etc. However, because of space limitations on the camera body, locating liquid crystal displays or rotary dials results in either a small, non-readable display, or increased cost and increased size of the camera. Furthermore, since display devices of cameras suffer limitations according to space and cost, in the past, only information restricted to the necessary minimum was displayed. Inessential and non-urgent information, for example, the cumulative number of exposed frames, was not displayed.
Previous rotating pointer type display devices have been unable to display adequate warning of certain failures and mistakes in the operation of the camera. For example, cameras are known that automatically set a combination of stop and shutter speed, when in a program exposure mode, according to the brightness of a photographic subject. When the combination of stop and shutter speed is sequentially changed (hereinbelow, this operation is termed xe2x80x9cprogram shiftxe2x80x9d), if either the stop or the shutter speed reaches a predetermined interlock limit, beyond which shutter speed cannot become faster, further program shift becomes impossible. However, conventional rotary pointer type display devices cannot display this state, even if the stop or the shutter speed reaches the interlock limit during a program shift. As a result, the program shift operation continues for a short time without a photographer recognizing this state of affairs.
It is therefore an object of the present invention to provide a display apparatus in a camera which makes displayed information easily viewable by a user.
It is a further object of the present invention to provide a camera display apparatus which is relatively small in size and relatively inexpensive.
Yet a further object of the present invention is to provide a rotary pointer type camera display apparatus which displays a plurality of information in a highly visible manner.
It is another object of the present invention to provide a camera display apparatus which provides true and accurate information indicating the operative state of the camera. Still a further object of the invention is to provide a camera display apparatus which changes from a display of frame count information to a display of the number of frames remaining for exposure when the number of exposures remaining becomes small.
Another object of the present invention is to provide a camera display apparatus wherein different types of display information are displayed on a single display using display pointers having plural indication ends which point to different display scales.
Yet another object of the present invention is to provide a camera display apparatus wherein the photographic frame count can be recognized instantly.
A further object of the invention is to provide a camera display apparatus having a single rotary pointer which indicates both frame count information in a normal mode of operation and time until exposure in a self-timing mode of operation.
Yet another object of the present invention is to provide a camera display apparatus which includes a small display located within a larger display wherein viewing of one display does not interfere with viewing of the other.
Yet a further object of the present invention is to provide a display apparatus in a camera which utilizes a single pointer and a plurality of pointer scales in order to display combinations of different information in a single display.
Still a further object of the present invention is to provide a rotary pointer analog-type display apparatus for a camera which can provide a warning display if the stop or shutter speed exceed an interlock limit during a program shift.
Yet another object of the present invention is to provide a display apparatus for a camera which includes display of inessential and non-urgent information.
The above objects are achieved by providing a display apparatus in a camera for displaying photographic information using rotating elements, comprising (a) means for generating camera control information; (b) display means, including at least one rotating pointer and at least one display scale having indices, for representing the photographic information; (c) drive means for rotating at least one rotating pointer to a position on the at least one display scale; and (d) control means responsive to the camera control information for controlling the drive means to rotate the at least one pointer to an index on the pointer scale representing the photographic information.